Rotary heat exchanger



Feb. 6, 1962 R. F. OMARA ROTARY,l HEAT EXCHANGER 2 Sheets-Sheet 1 Filed Aug. 29. 1957 "www Tom

INVENTOR.

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Feb. 6 1962 R. F. o'MARA 3,020,025

ROTARYI HEAT EXCHANGER Filed Aug. 29. 195? 2 Sheets-Sheet 2 INVENTOR.

United States Patent 3,020,025 ROTARY HEAT EXCHANGER Richard F. Mara, 839 S. Lorraine Blvd., Los Angeles, Calif. Filed Aug. 29, 1957, Ser. No. 680,942 4 Claims. (Cl. 257-79) This invention is directed generally to the provision of a heat exchanger adapted to be rotated during operation and particularly to such a device in the form o-f a double hollow shaft assembly having a number of lins or paddles spaced therealong including fins which may be selectively adjusted as to angular inclination and fins which employ a substantial portion of their volume for circulation of heat exchange fluid therein.

In its preferred form hereinafter shown and described, apparatus embodying the present invention includes a longitudinally extending trough or casing. When horizontally oriented, the lower portion of the trough is desirably but not necessarily provided with a cylindrically shaped inner wall. A double hollow shaft assembly extends the length of the trough or casing. The shaft assembly includes a central portion for the axial passage of a heat transfer fluid which may be steam, water or other desired liquid or gas. A larger hollow shaft surrounds and is fixed to the rst named hollow shaft and the annular space between the inner and outer shafts alfords a passageway for the heat transfer fluid axially of the shaft. Typically, the flow of iluid in the annular space may be opposite to the direction of fluid flow in the inner hollow shaft.

Spaced longitudinally along the shaft assembly just referred to are a number of radially projecting heat transfer assemblies. Each such assembly may include a pair of rigid pipes or conduits, one pipe of each assembly being substantially smaller than the other. The smallerpipe is ilxed to the inner hollow shaft so that tluid communication is established between the inner shaft and the interior of the smaller pipe. The outer pipe is connected to the outer of the hollow shafts, and the two pipes are arranged in coaxial relation with iluid communication existing between the annular space between the two pipes and the annular space between the two hollow shafts. The outer ends of the larger pipe is closed olf, so that fluid moving, for example, outwardly in the inner pipe must ilow inwardly in the annular space between the two pipes, there being no other outlet for such iluid. By preference, throttling means may be provided for selectively adjusting the effective cross-sectional area of iluid flow in the heat transfer assembly. Other return path means may be substituted for the outer pipe, as set forth hereinafter.

In connection with each of the heat transfer assemblies just mentioned there is provided a fin approximately in the shape of a circular sector. The n is supported on the outer of the two pipes of the heat transfer assembly and may be adjustably positioned rela* tive thereto by suitable means so that the plane of the fin assumes any desired angle relative to a plane perpendicular to the axis of the double shaft. Additional impeller tins may also be provided at spaced points along the shaft.

In another form of the invention the sector-shaped iin may be formed to have a hollow interior, and the outer pipe above referred to may then be omitted so that the return path of heat exchange fluid may include the entire hollow interior of the n, this construction providing for fluid communication between the fin interior and the annular space between the hollow shafts of the shaft assembly.

Because of the angular adjustability of the individual tins of the heat transfer assemblies as well as of the additional impeller fins, when used, the present heat exchanger is particularly valuable in many industrial processes involving the transfer of heat either to or from a quantity of flowable material. may be tluid in form or may be a granular or pasty solid; in the completed apparatus for carrying out the present invention, the trough or casing within which 'the apparatus described above is rotatably mounted is pro vided near one end with an inlet opening for the material to be treated and near the opposite endwith an outlet for such material. The entire apparatus may be oriented with the axis of the double shaft disposed horizontally, vertically or at any desired angle best suited for the particular process being carried out, and a plurality of the heat exchangers may be provided in rows or tiers with the fins of one heat exchanger -interfolded and meshing those of another.

Accordingly, the objects of the present invention are to provide a novel construction of heat exchange apparatus; to provide such an apparatus adapted to rotate during operation within a trough or casing; to provide such apparatus including a double hollow shaft for the axial movement of heat exchange fluid together with means for fluid flow outwardly and inwardly relative to the shaft and meansfor impelling material longitudinally of the casing; to provide a plurality of heat transfer assemblies each including a pair of coaxial radially extending pipes connected respectively to the interiors of the double hollow shaft; and to provide in connection with each of the heat transfer assemblies means for controllably adjusting iluid flow therein and impeller tins angularly adjustable around the axis of each heat transfer assemblies to control movement of material longitudinally of the shaft axis.

These and other and similar objects and purposes willA be understood Vfrom the following description of preferred embodiments of the invention taken in connection with the accompanying drawings, in which:

FIG. l is a longitudinal broken sectional view of a heat exchange apparatus embodying the invention.

FIG. 2 is a sectional view on line II-II of FIG. l.

FlG. 3 is a sectional view on line III-III of FIG. 1.

FIG. 4 is a sectional view on line IV-IV of FIG. l.

FIG. 5 is a sectional view of a hollow interior iin or paddle in accordance with the invention.

Referring in detail to the drawings in FIG. l, there is indicated generally at 1t) a longitudinally extending heat exchange conveyor including a trough or casing, the lower inner surface 12 being preferably cylindrical and extending the entire length of the apparatus. An inlet opening 14 is provided at one end of the apparatus, preferably in the upper portion thereof, and an outlet opening 16 is provided at the other end of the apparatus, preferably in the lower portion thereof, when the device is mounted with its axis horizontal. The inlet and outlet openings 14 and 16 may be connected to suitable conduits or other structures for bringing material to be treated to the heat exchanger and for conveying it therefrom following the heat exchange process.

Rotatably mounted within the heat exchanger 10 is a double hollow shaft indicated generally at 20 including an outer shaft 22 and coaxially mounted therein an inner shaft 24. As shown in the righthand portion of FIG. l, conventional rotary coupling and bearing means are provided for fluid communication with the hollow interior of shafts 22 and 2.4. Shaft 24 is coupled to an extension 25 which projects into cap 26 which may be connected to a conduit or the like Z7. Shaft 22 is coupled to an extension Z9 which communicates the annular space 30 between the shafts 22 and 2.4 with the interior of housing 3-1 and thereby with an exterior con` duit 32 for the iluid. The other end of the hollow shaft The material so treated shafts and removing the same from lthe interior of the other shaft; and means for rotating the shaft assembly.

2. In a rotary heat exchanger: means forming an elongated trough having a lower generally cylindrical inner surface; a double hollofw shaft assembly mounted for r0- tation in the trough lincluding an inner hollow shaft within an outer hollow shaft; a plurality of heat transfer assemblies in tluid communication with the interiors of said shafts and spaced therealong, each assembly including a conduit for leading tluid from the interior of one of said shafts radially outwardly, means for conveying said fluid from Ithe end of the conduit into the interior of the other said shatit, impeller n means in heat transfer relation with the `conveyed uid and with owable material in the trough and having an arcuate outer edge adapted to sweep adjacent said cylindrical surface during rotation of the shaft assembly in the trough and means for securing the n means with its elective plane at a selected angle relative to a plane perpendicular to the axis of said shaft assembly; and means for supplying heat transfer fluid .-to the interior of one of said shafts and removing the same from the interior of the other said shaft.

3. The invention as stated in claim k2 wherein said conveying means comprise a generally sector-shaped cav# ity formed within said impeller iin means and surrounding said conduit. v

4. The invention as stated in claim 2 Iwherein said con veying means comprise a pipe concentric ywith and surrounding said conduit.

References Cited in the file of this patent UNITED STATES PATENTS 208,705 Bazemore Oct. 8, 1878 1,355,137` Frick Oct. 12, 1920 1,689,189 Broadhurst Oct. 30, 1928 1,818,082 Mott Aug. 11, 1931 2,027,185 Loomis Jan. 7, 1936 2,160,533 Bonath May 30, 1939 FOREIGN PATENTS 59,016 Norway Feb. 2:1, 1938 764,544 Great Britain Dec. 28, 1956 1,127,505 France Aug. 13, 1956 

